I had sex 10 days ago. Twice. I have been on the pill for a while, but I miss a lot and take them at different times (but always in the AM). The guy did not come inside me. Last week I was bleeding heavy like I was on my period, but I had still been taking my pill! (not placebo!) today, this happened. Is this implantation?! Is it possible to be pregnant even if I bled like a period last week for about 3-4 days? Or is this old blood?